How to Make It
Step 1
Preheat oven to 400°F. Stem 6 (5-inch) portobello mushrooms and scrape out gills with a spoon. Brush 1 1/2 Tbsp. olive oil all over mushrooms. Place on a large, rimmed nonstick baking sheet, hollow side up. Bake for 10 minutes and remove from oven. (Leave oven on.)
Step 2
Using paper towels, blot excess moisture from mushroom cavities and season with salt and pepper. Spread 1 Tbsp. jarred pizza sauce in cavity of each mushroom. Divide 2 oz. sliced turkey pepperoni and 1 green pepper, seeded and thinly sliced, evenly among mushroom caps. Top each with 1/4 cup shredded Italian four-cheese blend.
Step 3
Return mushrooms to oven and bake until cheese is bubbling, about 10 minutes. Serve hot.